1. Field of the Invention
The present invention relates to a refrigerant composition useful as a refrigerant for a refrigerator, an air-conditioner, etc.
2. Description of the Background Art
Chlorofluorocarbon (hereinafter referred to as xe2x80x9cCFCxe2x80x9d) compound, which were used as a refrigerant, have been restricted in production and use according to the Montreal Protocol because they have been found as a main factor in contributing to the destruction of the ozone layer in a stratosphere. In developed countries, the use of such CFC compounds have already been banned since 1996. It is also known that hydrochlorofluorocarbon (hereinafter referred to as xe2x80x9cHCFCxe2x80x9d) compounds such as HCFC-22 have considerable effects in causing damage to the ozone layer even though this effect is less severe than that of CFC compounds. For this reason, a restriction has been made to gradually reduce the use of HCFC compounds. A plan has also been made to ban the use of HCFC about 2030. In preparation of the full-scale restriction to the HCFC-22, many countries around the world are making a heavy investment to develop a refrigerant that can substitute HCFC-22.
However, it is well known that it is difficult to obtain a performance coefficient similar to that of HCFC-22 with a single material. One of methods to solve the above-mentioned problem would be to use of a mixed refrigerant having similar physical properties to that of HCFC-22.
Namely, a mixed refrigerant has advantages in that by controlling a composition of the mixed refrigerant, almost the same vapor pressure as the conventional refrigerant can be achieved, the same lubricant can be used, and the compressor needs not to be replaced. For this reason, several different types of mixed refrigerants have been developed as a substitute for HCFC-22 for the past several years.
Representative examples of a refrigerant composition developed as a substitute for HCFC-22 are HFC-407C and HFC-410A proposed by the American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE). HFC-407C is a refrigerant composition of HFC-32/125/134a in a ration of 23/25/52 based on weight percent. Meanwhile, HFC-410A is a refrigerant composition of HFC-32/125 in a ratio of 50/50 based on weight percent.
In addition, U.S. Pat. No. 5,080,823 discloses a refrigerant composition of HFC-143a/propane, U.S. Pat. No. 5,211,867: HFC-125/143a, U.S. Pat. No. 5,234,613: HFC-32/propane, U.S. Pat. No. 5,236,611: PFC-218/HFC-143a, U.S. Pat. No. 5,290,466: HFC-32/134a/134, U.S. Pat. No. 5,340,490: HFC-23/CO2 and HFC-23/116/CO2, U.S. Pat. No. 5,403,504: HFC-125/32, U.S. Pat. No. 5,429,740: HFC-23/134a U.S. Pat. No. 5,538,660: HFC-32/HFC-134a/FC-41 and HFC-32/HFC-134a/PFC-218, and U.S. Pat. No. 5,643,492: HFC-32/125/134a.
Also, Japanese Patent Laid-open Publication No. 172386/1991 discloses a refrigerant composition of HFC-32/125/143a, Japanese Patent Laid-open Publication No. 170594/1991: HFC-23/125/134a, Japanese Patent Laid-open Publication No. 170593/1991: HFC-23/125/32, Japanese Patent Laid-open Publication No. 170591/1991: HFC-23/143a/134a, Japanese Patent Laid-open Publication No. 170590/1991: HFC-125/134a/32, Japanese Patent Laid-open Publication No. 170589/1991: HFC-23/143a/152a, Japanese Patent Laid-open Publication No. 170588/1991: HFC-125/143a/134a, Japanese Patent Laid-open Publication No. 170585/1991: HFC-32/125/134a, Japanese Patent Laid-open Publication No. 170584/1991: HFC-23/134a/152a, Japanese Patent Laid-open Publication No. 170583/1991: HFC-1251143a/32, Japanese Patent Laid-open Publication No. 222893/1992: HFC-32/125, Japanese Patent Laid-open Publication No. 154887/1992: HFC-134/152a, Japanese Patent Laid-open Publication No. 117645/1993: HFC-23/134a/propane, Japanese Patent Laid-open Publication No. 117643/1993: HFC-125/134a/propane, Japanese Patent Laid-open Publication No. 65561/1994: HFC-23/152a/PFC-218, Japanese Patent Laid-open Publication No. 128872/1994: HFC-32/PFC-218, Japanese Patent Laid-open Publication No. 220433/1994: HFC-32/125/RC-318, Japanese Patent Laid-open Publication No. 173462/1995: HFC-143a/125/134a/heptane, Japanese Patent Laid-open Publication No. 176537/1996: PFC-218/RC-270/HFC-152a, Japanese Patent Laid-open Publication No. 151569/1996: propane/RC-270/HFC-134a, Japanese Patent Laid-open Publication No. 127767/1996: HFC-32/134a/RC-318, Japanese Patent Laid-open Publication No. 25480/1997: HFC-32/134a/125/isobutane, Japanese Patent Laid-open Publication No. 59611/1997: HFC-134a/isobutane, Japanese Patent Laid-open Publication No. 208941/1997: HFC-32/152a/125/RC-270, and Japanese Patent Laid-open Publication No. 221664/1997: HFC-125/143a/134a/RC-270.
Also, Korean Patent Laid-open Publication No. 91-9902 discloses a refrigerant composition of HFC-23/32/152a, HFC-23/125/152a, HFC-32/143a/152a, HFC-125/143a/152a, HFC-32/125/125a and HFC-23/143a/152a, Korean Patent Laid-open Publication No. 91-9903: HFC-23/32/134, HFC-23/32/134a, HFC-23/125/134, HFC-32/125/134, HFC-23/143a/134a, HFC-125/143a/134a and HFC-125/143a/134, Korean Patent Laid-open Publication No. 96-4485: HFC-32/23/134a, Korean Patent Laid-open Publication No. 96-701168: HFC-227ea/HFC-152a, and Korean Patent Laid-open Publication No. 97-704853: HFC-134a/HCFC-124/butane.
Such various types of mixed refrigerants as mentioned above are being applied to a refrigerator, an air-conditioner, etc.
Therefore, an object of the present invention is to provide a refrigerant composition which has a novel composition, exhibits a similar performance to that of HCFC-22, has no possibility of damaging the ozone layer, and accordingly can be used as a substitute for HCFC-22.